This is a survey of the economic principles that underlie antitrust law and how those principles relate to competition policy. We address four core subject areas: market power, collusion, mergers between competitors, and monopolization. In each area, we select the most relevant portions of...

We test whether firms use incompatibility strategically, using data from ATM markets. High ATM fees degrade the value of competitors' deposit accounts, and can in principle serve as a mechanism for siphoning depositors away from competitors or for creating deposit account differentiation. Our...

This paper provides a framework to classify and evaluate the impact of net neutrality regulations on the allocation of consumer attention and the distribution of surplus between consumers, ISPs and content providers. While the model provided largely nests other contributions in the literature,...

This paper provides a new explanation for tying that is not based on any of the standard explanations -- efficiency, price discrimination, and exclusion. Our analysis shows how a monopolist sometimes has an incentive to tie a complementary good to its monopolized good in order to transfer...

An upstream manufacturer can use minimum retail price maintenance (RPM) to exclude potential competitors. RPM lets the incumbent manufacturer transfer profits to retailers. If entry is accommodated, upstream competition leads to fierce down- stream competition and the breakdown of RPM. Hence,...

This paper reports the results of an experiment designed to assess the ability of an incumbent seller to profitably foreclose a market with exclusive contracts. We use the strategic environment described by Rasmusen, Ramseyer, and Wiley (1991) and Segal and Whinston (2000) where entry is...

Standard policies to correct market power and selection can be misguided when these two forces co-exist. Using a calibrated model of employer-sponsored health insurance, we show that the risk adjustment commonly used by employers to offset adverse selection often reduces the amount of...

The one-shot nature of most theoretical models of strategic investment, especially those based on asymmetric information, limits our ability to test whether they can fit the data. We develop a dynamic version of the classic Milgrom and Roberts (1982) model of limit pricing, where a monopolist...

I discuss the antitrust suit brought by the U.S. Department of Justice against Visa and MasterCard in 1998. Banks that issue Visa cards are free to also issue MasterCard cards, and vice versa, and many banks issue the cards of both networks. However, both Visa and MasterCard had rules...

Since the passage of the Interstate Commerce Act (1897) and the Sherman Act (1890), regulation and antitrust have operated as competing mechanisms to control competition. Regulation produced cross-subsidies and favors to special interests, but specified prices and rules of mandatory dealing....